Acid value is used as a mandatory indicator in China to measure the degree of spoilage of meat and meat products. Before determining the acid value of meat and meat products, it is necessary to extract the oil and fat with petroleum ether, and then use the extracted oil and fat to determine the acid value of the oil and fat according to the method for determining the acid value of oil and fat. The transportation of imported and exported pet feed takes a lot of time, so its shelf life can be estimated based on the acid value of the feed. Therefore, the determination of acid value has become very meaningful in this industry.